“When an alarm from the built-in Clock app fires, it fades out in volume as soon as you look at the display. This is utterly charming.”

I shared this fact with my wife — who does not work in tech! — but who said, “You know what they’ll use that for? They’ll use it for advertising. To make sure you’re paying attention.”

I immediately thought of how, in the ad-supported version of Spotify, lowering the volume during a commercial automatically pauses whatever ad is playing.

Now, the truth is that Apple doesn’t let apps utilize the front-facing camera without permission. (And, separately, Apple’s latest Security Guide makes it clear just how secure Face ID is). But for apps that might request permission to use the camera upfront (like a photo filters app, or game, or YouTube), one can conceive of the possibility of those apps also using simultaneous facial tracking to see if there are actually eyeballs on ads. To be clear, I’m fairly certain Apple’s system of sandboxing and the iPhone’s Secure Enclave would not allow facial data to be transmitted, but it’s an interesting thought experiment.

Taking this to its logical – and unseemly – conclusion, it’s conceivable that an interstitial ad on YouTube might stop playing if you looked away – what a awful thought! But it’s also one of those situations where, even if a company could do it, would you really want to be the company that would watch your users – or their anonymized facial data – as they watch your content?